North Coast politicians and transit supporters gathered in Petaluma on Friday for a ceremonial groundbreaking for the SMART commute train that will run between Sonoma and Marin counties.

"This is a historic moment, it has been a long time coming," said Rep. Lynn Woolsey, D-Petaluma. "We simply can't meet our transportation needs by building roads. It's not cost-effective. It is not smart."

The ceremony was held at the historic Petaluma depot and attracted a crowd of 400, a large number of whom took turns with the 49 golden shovels to turn over a mound of dirt crossing the tracks.

The gathering came 30 years after politicians in both counties began working to preserve the Northwestern Pacific Railroad right-of-way as a future transit corridor, a decade after the rail transit district was formed and four years after voters passed a quarter-cent sales tax to fund the train.

"It's been a long road," said Cloverdale Councilwoman Carol Russell, a director of the rail agency, Sonoma-Marin Area Regional Transit. "It is how long it took to build the Golden Gate Bridge."

The agency has faced multiple challenges over the past four years, with a recession forcing SMART to scale back the initial line and delay the beginning of service. In addition, missteps by the SMART board that may have eroded some public confidence prompted an unsuccessful tax repeal effort.

SMART Chairwoman Valerie Brown, a Sonoma County supervisor, said the effort to repeal the sales tax, passed by 70 percent of Sonoma and Marin voters in November 2008, was the most troubling.

"That was absolutely a worry, that we had to be back on the ballot and fight it out again," Brown said.

The event also was attended by Rep. Mike Thompson, D-St. Helena; state senators Noreen Evans, D-Santa Rosa, and Mark Leno, D-San Francisco; and state assembly members Mike Allen, D-San Rafael; Wes Chesbro, D-Arcata; and Jared Huffman,?D-San Rafael.

In the past two months, SMART has sold construction bonds and awarded a $103 million contract for the initial work to build the line and stations from Gureneville Road in Santa Rosa to the Marin Civic Center in San Rafael.

It is preparing to award another construction contract within the next few months to build between the Civic Center and downtown San Rafael.

Trains are scheduled to begin running on the initial line, 38.5 miles, in late 2014 or early 2015.

The line is to be extended north to Cloverdale and south to Larkspur as additional funds become available.